<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<form action="target.html" autocomplete="off">
    <!--
        autocomplete="off" 关闭自动补全
        readonly 设置表单项设置为只读
        disabled 设置表单项为禁用
        autofocus 设置表单项自动获取焦点
    -->
    <input type="text" name="username" value="hello" readonly>
    <input type="text" name="a" autofocus>
    <input type="text" name="b" >

    <br><br>

    <input type="color">

    <input type="submit">

    <!--重置按钮-->
    <input type="reset">
    <!--普通按钮-->
    <input type="button" value="按钮">

    <br>
    <button type="submit">提交</button>
    <button type="reset">重置</button>
    <button type="button">按钮</button>
</form>
</body>
</html>